Hi all,

New owner of a 2003 Yukon XL 2500 4WD SLT. I have a few questions:

1. There's a faint sound like a small electric motor when I turn the key on, that seems like it's coming from mid to rear of the truck. It just turned up this morning, I haven't heard it in the last week. It comes on with the key, engine running or not. It lasts until I turn the key off, when it winds down and stops. The climate control is turned off front and rear. It seems to have gone away the next time I drove it.

2. I don't seem to be getting 12v power from the 7-pin trailer connector's charge line. Is there something I need to install to enable this? I've read about a fuse I need to add?

3. The previous owner installed an AUX input in the dash using some sort of adapter device interfaced to the head unit, but I haven't been able to figure out how to use it. The head unit is the stock 6CD changer with XM radio. Any ideas on what might have been installed before I open up the dash to look at the device?

4. Is there a way to have the fogs come on with the headlights?

 

Welcome to the forum.

1. Not sure what that could be.

2. I think there's a pigtail near/in the fuse box under the hood that needs to be connected for the trlr brake controller power battery.

3. Might try plugging a MP3 player or iPod in and see what u get.

4. Use a relay activated by the headlite power. Why?

 

not sure about the other stuff you talked about but the sound.... the next time u turn the key go to the gas tank and listen im pretty sure that its just your fuel pump my 96 suburban does the same thing. its just the pump running power to prime the line before starting.